Had this issue. Put Rachio Gen 3 on a separate wireless router and gave it a static IP address. This fixed my issue. I have not tested yet but I think you can set some range extenders for fix IP address which may be an easy fix. Had the Rachio on my home central wireless network which is quite complex with alarm systems and surveillance cameras, iPhones, iPads, TVs etc. It would go offline often. Hope this helps…
M